1. Preheat your oven to 350 degrees. Defrost your pie crust according to package instructions (may need to leave out at room temperature for up to 1 hour.
2. Generously grease a 9 inch pie plate. Lay your pie crust in your dish, crimping the edges with your fingers. Set aside.
3. Melt the butter and set aside to cool.
4. In a large bowl, whisk eggs and milk together. Slowly whisk in butter, brown sugar and vanilla until smooth. Fold in pecans, salt, and flour. Mix to combine.
5. Pour into pie shell. Bake at 350 degrees for 45-55 minutes (depending on oven). Crust should be golden brown, pie should be firm, but still slightly jiggly in the middle. It will set as it cools.
6. Serve at room temperature with whipped cream or vanilla ice cream.